The third argument to this function indicates whether the supplied ticker is fixed or variable, i.e. requiring calibration. Give this argument a type and name that better conveys this purpose. Reviewed by: kib, markj MFC after: 1 week Sponsored by: The FreeBSD Foundation Differential Revision: https://reviews.freebsd.org/D35459
2264 lines
56 KiB
C
2264 lines
56 KiB
C
/*-
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* SPDX-License-Identifier: Beerware
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*
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* ----------------------------------------------------------------------------
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* "THE BEER-WARE LICENSE" (Revision 42):
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* <phk@FreeBSD.ORG> wrote this file. As long as you retain this notice you
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* can do whatever you want with this stuff. If we meet some day, and you think
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* this stuff is worth it, you can buy me a beer in return. Poul-Henning Kamp
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* ----------------------------------------------------------------------------
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*
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* Copyright (c) 2011, 2015, 2016 The FreeBSD Foundation
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*
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* Portions of this software were developed by Julien Ridoux at the University
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* of Melbourne under sponsorship from the FreeBSD Foundation.
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*
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* Portions of this software were developed by Konstantin Belousov
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* under sponsorship from the FreeBSD Foundation.
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*/
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#include <sys/cdefs.h>
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__FBSDID("$FreeBSD$");
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#include "opt_ntp.h"
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#include "opt_ffclock.h"
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#include <sys/param.h>
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#include <sys/kernel.h>
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#include <sys/limits.h>
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#include <sys/lock.h>
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#include <sys/mutex.h>
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#include <sys/proc.h>
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#include <sys/sbuf.h>
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#include <sys/sleepqueue.h>
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#include <sys/sysctl.h>
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#include <sys/syslog.h>
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#include <sys/systm.h>
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#include <sys/timeffc.h>
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#include <sys/timepps.h>
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#include <sys/timetc.h>
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#include <sys/timex.h>
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#include <sys/vdso.h>
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/*
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* A large step happens on boot. This constant detects such steps.
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* It is relatively small so that ntp_update_second gets called enough
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* in the typical 'missed a couple of seconds' case, but doesn't loop
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* forever when the time step is large.
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*/
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#define LARGE_STEP 200
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/*
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* Implement a dummy timecounter which we can use until we get a real one
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* in the air. This allows the console and other early stuff to use
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* time services.
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*/
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static u_int
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dummy_get_timecount(struct timecounter *tc)
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{
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static u_int now;
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return (++now);
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}
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static struct timecounter dummy_timecounter = {
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dummy_get_timecount, 0, ~0u, 1000000, "dummy", -1000000
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};
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struct timehands {
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/* These fields must be initialized by the driver. */
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struct timecounter *th_counter;
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int64_t th_adjustment;
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uint64_t th_scale;
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u_int th_large_delta;
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u_int th_offset_count;
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struct bintime th_offset;
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struct bintime th_bintime;
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struct timeval th_microtime;
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struct timespec th_nanotime;
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struct bintime th_boottime;
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/* Fields not to be copied in tc_windup start with th_generation. */
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u_int th_generation;
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struct timehands *th_next;
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};
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static struct timehands ths[16] = {
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[0] = {
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.th_counter = &dummy_timecounter,
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.th_scale = (uint64_t)-1 / 1000000,
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.th_large_delta = 1000000,
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.th_offset = { .sec = 1 },
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.th_generation = 1,
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},
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};
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static struct timehands *volatile timehands = &ths[0];
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struct timecounter *timecounter = &dummy_timecounter;
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static struct timecounter *timecounters = &dummy_timecounter;
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/* Mutex to protect the timecounter list. */
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static struct mtx tc_lock;
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int tc_min_ticktock_freq = 1;
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volatile time_t time_second = 1;
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volatile time_t time_uptime = 1;
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/*
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* The system time is always computed by summing the estimated boot time and the
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* system uptime. The timehands track boot time, but it changes when the system
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* time is set by the user, stepped by ntpd or adjusted when resuming. It
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* is set to new_time - uptime.
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*/
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static int sysctl_kern_boottime(SYSCTL_HANDLER_ARGS);
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SYSCTL_PROC(_kern, KERN_BOOTTIME, boottime,
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CTLTYPE_STRUCT | CTLFLAG_RD | CTLFLAG_MPSAFE, NULL, 0,
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sysctl_kern_boottime, "S,timeval",
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"Estimated system boottime");
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SYSCTL_NODE(_kern, OID_AUTO, timecounter, CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
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"");
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static SYSCTL_NODE(_kern_timecounter, OID_AUTO, tc,
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CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
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"");
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static int timestepwarnings;
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SYSCTL_INT(_kern_timecounter, OID_AUTO, stepwarnings, CTLFLAG_RWTUN,
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×tepwarnings, 0, "Log time steps");
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static int timehands_count = 2;
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SYSCTL_INT(_kern_timecounter, OID_AUTO, timehands_count,
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CTLFLAG_RDTUN | CTLFLAG_NOFETCH,
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&timehands_count, 0, "Count of timehands in rotation");
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struct bintime bt_timethreshold;
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struct bintime bt_tickthreshold;
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sbintime_t sbt_timethreshold;
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sbintime_t sbt_tickthreshold;
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struct bintime tc_tick_bt;
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sbintime_t tc_tick_sbt;
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int tc_precexp;
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int tc_timepercentage = TC_DEFAULTPERC;
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static int sysctl_kern_timecounter_adjprecision(SYSCTL_HANDLER_ARGS);
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SYSCTL_PROC(_kern_timecounter, OID_AUTO, alloweddeviation,
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CTLTYPE_INT | CTLFLAG_RWTUN | CTLFLAG_MPSAFE, 0, 0,
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sysctl_kern_timecounter_adjprecision, "I",
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"Allowed time interval deviation in percents");
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volatile int rtc_generation = 1;
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static int tc_chosen; /* Non-zero if a specific tc was chosen via sysctl. */
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static char tc_from_tunable[16];
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static void tc_windup(struct bintime *new_boottimebin);
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static void cpu_tick_calibrate(int);
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void dtrace_getnanotime(struct timespec *tsp);
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void dtrace_getnanouptime(struct timespec *tsp);
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static int
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sysctl_kern_boottime(SYSCTL_HANDLER_ARGS)
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{
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struct timeval boottime;
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getboottime(&boottime);
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/* i386 is the only arch which uses a 32bits time_t */
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#ifdef __amd64__
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#ifdef SCTL_MASK32
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int tv[2];
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if (req->flags & SCTL_MASK32) {
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tv[0] = boottime.tv_sec;
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tv[1] = boottime.tv_usec;
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return (SYSCTL_OUT(req, tv, sizeof(tv)));
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}
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#endif
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#endif
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return (SYSCTL_OUT(req, &boottime, sizeof(boottime)));
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}
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static int
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sysctl_kern_timecounter_get(SYSCTL_HANDLER_ARGS)
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{
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u_int ncount;
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struct timecounter *tc = arg1;
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ncount = tc->tc_get_timecount(tc);
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return (sysctl_handle_int(oidp, &ncount, 0, req));
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}
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static int
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sysctl_kern_timecounter_freq(SYSCTL_HANDLER_ARGS)
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{
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uint64_t freq;
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struct timecounter *tc = arg1;
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freq = tc->tc_frequency;
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return (sysctl_handle_64(oidp, &freq, 0, req));
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}
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/*
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* Return the difference between the timehands' counter value now and what
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* was when we copied it to the timehands' offset_count.
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*/
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static __inline u_int
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tc_delta(struct timehands *th)
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{
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struct timecounter *tc;
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tc = th->th_counter;
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return ((tc->tc_get_timecount(tc) - th->th_offset_count) &
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tc->tc_counter_mask);
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}
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static __inline void
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bintime_add_tc_delta(struct bintime *bt, uint64_t scale,
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uint64_t large_delta, uint64_t delta)
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{
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uint64_t x;
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if (__predict_false(delta >= large_delta)) {
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/* Avoid overflow for scale * delta. */
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x = (scale >> 32) * delta;
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bt->sec += x >> 32;
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bintime_addx(bt, x << 32);
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bintime_addx(bt, (scale & 0xffffffff) * delta);
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} else {
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bintime_addx(bt, scale * delta);
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}
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}
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/*
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* Functions for reading the time. We have to loop until we are sure that
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* the timehands that we operated on was not updated under our feet. See
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* the comment in <sys/time.h> for a description of these 12 functions.
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*/
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static __inline void
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bintime_off(struct bintime *bt, u_int off)
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{
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struct timehands *th;
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struct bintime *btp;
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uint64_t scale;
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u_int delta, gen, large_delta;
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do {
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th = timehands;
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gen = atomic_load_acq_int(&th->th_generation);
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btp = (struct bintime *)((vm_offset_t)th + off);
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*bt = *btp;
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scale = th->th_scale;
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delta = tc_delta(th);
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large_delta = th->th_large_delta;
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atomic_thread_fence_acq();
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} while (gen == 0 || gen != th->th_generation);
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bintime_add_tc_delta(bt, scale, large_delta, delta);
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}
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#define GETTHBINTIME(dst, member) \
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do { \
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_Static_assert(_Generic(((struct timehands *)NULL)->member, \
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struct bintime: 1, default: 0) == 1, \
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"struct timehands member is not of struct bintime type"); \
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bintime_off(dst, __offsetof(struct timehands, member)); \
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} while (0)
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static __inline void
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getthmember(void *out, size_t out_size, u_int off)
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{
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struct timehands *th;
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u_int gen;
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do {
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th = timehands;
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gen = atomic_load_acq_int(&th->th_generation);
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memcpy(out, (char *)th + off, out_size);
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atomic_thread_fence_acq();
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} while (gen == 0 || gen != th->th_generation);
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}
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#define GETTHMEMBER(dst, member) \
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do { \
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_Static_assert(_Generic(*dst, \
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__typeof(((struct timehands *)NULL)->member): 1, \
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default: 0) == 1, \
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"*dst and struct timehands member have different types"); \
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getthmember(dst, sizeof(*dst), __offsetof(struct timehands, \
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member)); \
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} while (0)
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#ifdef FFCLOCK
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void
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fbclock_binuptime(struct bintime *bt)
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{
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GETTHBINTIME(bt, th_offset);
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}
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void
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fbclock_nanouptime(struct timespec *tsp)
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{
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struct bintime bt;
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fbclock_binuptime(&bt);
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bintime2timespec(&bt, tsp);
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}
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void
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fbclock_microuptime(struct timeval *tvp)
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{
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struct bintime bt;
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fbclock_binuptime(&bt);
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bintime2timeval(&bt, tvp);
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}
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void
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fbclock_bintime(struct bintime *bt)
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{
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GETTHBINTIME(bt, th_bintime);
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}
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void
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fbclock_nanotime(struct timespec *tsp)
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{
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struct bintime bt;
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fbclock_bintime(&bt);
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bintime2timespec(&bt, tsp);
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}
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void
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fbclock_microtime(struct timeval *tvp)
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{
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struct bintime bt;
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fbclock_bintime(&bt);
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bintime2timeval(&bt, tvp);
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}
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void
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fbclock_getbinuptime(struct bintime *bt)
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{
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GETTHMEMBER(bt, th_offset);
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}
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void
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fbclock_getnanouptime(struct timespec *tsp)
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{
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struct bintime bt;
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GETTHMEMBER(&bt, th_offset);
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bintime2timespec(&bt, tsp);
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}
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void
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fbclock_getmicrouptime(struct timeval *tvp)
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{
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struct bintime bt;
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GETTHMEMBER(&bt, th_offset);
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bintime2timeval(&bt, tvp);
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}
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void
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fbclock_getbintime(struct bintime *bt)
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{
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GETTHMEMBER(bt, th_bintime);
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}
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void
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fbclock_getnanotime(struct timespec *tsp)
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{
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GETTHMEMBER(tsp, th_nanotime);
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}
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void
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fbclock_getmicrotime(struct timeval *tvp)
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{
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GETTHMEMBER(tvp, th_microtime);
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}
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#else /* !FFCLOCK */
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void
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binuptime(struct bintime *bt)
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{
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GETTHBINTIME(bt, th_offset);
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}
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void
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nanouptime(struct timespec *tsp)
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{
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struct bintime bt;
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binuptime(&bt);
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bintime2timespec(&bt, tsp);
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}
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void
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microuptime(struct timeval *tvp)
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{
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struct bintime bt;
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binuptime(&bt);
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bintime2timeval(&bt, tvp);
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}
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void
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bintime(struct bintime *bt)
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{
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GETTHBINTIME(bt, th_bintime);
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}
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void
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nanotime(struct timespec *tsp)
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{
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struct bintime bt;
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bintime(&bt);
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bintime2timespec(&bt, tsp);
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}
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void
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microtime(struct timeval *tvp)
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{
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struct bintime bt;
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bintime(&bt);
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bintime2timeval(&bt, tvp);
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}
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void
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getbinuptime(struct bintime *bt)
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{
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GETTHMEMBER(bt, th_offset);
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}
|
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|
|
void
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getnanouptime(struct timespec *tsp)
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{
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struct bintime bt;
|
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GETTHMEMBER(&bt, th_offset);
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bintime2timespec(&bt, tsp);
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}
|
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|
|
void
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getmicrouptime(struct timeval *tvp)
|
|
{
|
|
struct bintime bt;
|
|
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|
GETTHMEMBER(&bt, th_offset);
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bintime2timeval(&bt, tvp);
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}
|
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|
|
void
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|
getbintime(struct bintime *bt)
|
|
{
|
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|
GETTHMEMBER(bt, th_bintime);
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|
}
|
|
|
|
void
|
|
getnanotime(struct timespec *tsp)
|
|
{
|
|
|
|
GETTHMEMBER(tsp, th_nanotime);
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|
}
|
|
|
|
void
|
|
getmicrotime(struct timeval *tvp)
|
|
{
|
|
|
|
GETTHMEMBER(tvp, th_microtime);
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|
}
|
|
#endif /* FFCLOCK */
|
|
|
|
void
|
|
getboottime(struct timeval *boottime)
|
|
{
|
|
struct bintime boottimebin;
|
|
|
|
getboottimebin(&boottimebin);
|
|
bintime2timeval(&boottimebin, boottime);
|
|
}
|
|
|
|
void
|
|
getboottimebin(struct bintime *boottimebin)
|
|
{
|
|
|
|
GETTHMEMBER(boottimebin, th_boottime);
|
|
}
|
|
|
|
#ifdef FFCLOCK
|
|
/*
|
|
* Support for feed-forward synchronization algorithms. This is heavily inspired
|
|
* by the timehands mechanism but kept independent from it. *_windup() functions
|
|
* have some connection to avoid accessing the timecounter hardware more than
|
|
* necessary.
|
|
*/
|
|
|
|
/* Feed-forward clock estimates kept updated by the synchronization daemon. */
|
|
struct ffclock_estimate ffclock_estimate;
|
|
struct bintime ffclock_boottime; /* Feed-forward boot time estimate. */
|
|
uint32_t ffclock_status; /* Feed-forward clock status. */
|
|
int8_t ffclock_updated; /* New estimates are available. */
|
|
struct mtx ffclock_mtx; /* Mutex on ffclock_estimate. */
|
|
|
|
struct fftimehands {
|
|
struct ffclock_estimate cest;
|
|
struct bintime tick_time;
|
|
struct bintime tick_time_lerp;
|
|
ffcounter tick_ffcount;
|
|
uint64_t period_lerp;
|
|
volatile uint8_t gen;
|
|
struct fftimehands *next;
|
|
};
|
|
|
|
#define NUM_ELEMENTS(x) (sizeof(x) / sizeof(*x))
|
|
|
|
static struct fftimehands ffth[10];
|
|
static struct fftimehands *volatile fftimehands = ffth;
|
|
|
|
static void
|
|
ffclock_init(void)
|
|
{
|
|
struct fftimehands *cur;
|
|
struct fftimehands *last;
|
|
|
|
memset(ffth, 0, sizeof(ffth));
|
|
|
|
last = ffth + NUM_ELEMENTS(ffth) - 1;
|
|
for (cur = ffth; cur < last; cur++)
|
|
cur->next = cur + 1;
|
|
last->next = ffth;
|
|
|
|
ffclock_updated = 0;
|
|
ffclock_status = FFCLOCK_STA_UNSYNC;
|
|
mtx_init(&ffclock_mtx, "ffclock lock", NULL, MTX_DEF);
|
|
}
|
|
|
|
/*
|
|
* Reset the feed-forward clock estimates. Called from inittodr() to get things
|
|
* kick started and uses the timecounter nominal frequency as a first period
|
|
* estimate. Note: this function may be called several time just after boot.
|
|
* Note: this is the only function that sets the value of boot time for the
|
|
* monotonic (i.e. uptime) version of the feed-forward clock.
|
|
*/
|
|
void
|
|
ffclock_reset_clock(struct timespec *ts)
|
|
{
|
|
struct timecounter *tc;
|
|
struct ffclock_estimate cest;
|
|
|
|
tc = timehands->th_counter;
|
|
memset(&cest, 0, sizeof(struct ffclock_estimate));
|
|
|
|
timespec2bintime(ts, &ffclock_boottime);
|
|
timespec2bintime(ts, &(cest.update_time));
|
|
ffclock_read_counter(&cest.update_ffcount);
|
|
cest.leapsec_next = 0;
|
|
cest.period = ((1ULL << 63) / tc->tc_frequency) << 1;
|
|
cest.errb_abs = 0;
|
|
cest.errb_rate = 0;
|
|
cest.status = FFCLOCK_STA_UNSYNC;
|
|
cest.leapsec_total = 0;
|
|
cest.leapsec = 0;
|
|
|
|
mtx_lock(&ffclock_mtx);
|
|
bcopy(&cest, &ffclock_estimate, sizeof(struct ffclock_estimate));
|
|
ffclock_updated = INT8_MAX;
|
|
mtx_unlock(&ffclock_mtx);
|
|
|
|
printf("ffclock reset: %s (%llu Hz), time = %ld.%09lu\n", tc->tc_name,
|
|
(unsigned long long)tc->tc_frequency, (long)ts->tv_sec,
|
|
(unsigned long)ts->tv_nsec);
|
|
}
|
|
|
|
/*
|
|
* Sub-routine to convert a time interval measured in RAW counter units to time
|
|
* in seconds stored in bintime format.
|
|
* NOTE: bintime_mul requires u_int, but the value of the ffcounter may be
|
|
* larger than the max value of u_int (on 32 bit architecture). Loop to consume
|
|
* extra cycles.
|
|
*/
|
|
static void
|
|
ffclock_convert_delta(ffcounter ffdelta, uint64_t period, struct bintime *bt)
|
|
{
|
|
struct bintime bt2;
|
|
ffcounter delta, delta_max;
|
|
|
|
delta_max = (1ULL << (8 * sizeof(unsigned int))) - 1;
|
|
bintime_clear(bt);
|
|
do {
|
|
if (ffdelta > delta_max)
|
|
delta = delta_max;
|
|
else
|
|
delta = ffdelta;
|
|
bt2.sec = 0;
|
|
bt2.frac = period;
|
|
bintime_mul(&bt2, (unsigned int)delta);
|
|
bintime_add(bt, &bt2);
|
|
ffdelta -= delta;
|
|
} while (ffdelta > 0);
|
|
}
|
|
|
|
/*
|
|
* Update the fftimehands.
|
|
* Push the tick ffcount and time(s) forward based on current clock estimate.
|
|
* The conversion from ffcounter to bintime relies on the difference clock
|
|
* principle, whose accuracy relies on computing small time intervals. If a new
|
|
* clock estimate has been passed by the synchronisation daemon, make it
|
|
* current, and compute the linear interpolation for monotonic time if needed.
|
|
*/
|
|
static void
|
|
ffclock_windup(unsigned int delta)
|
|
{
|
|
struct ffclock_estimate *cest;
|
|
struct fftimehands *ffth;
|
|
struct bintime bt, gap_lerp;
|
|
ffcounter ffdelta;
|
|
uint64_t frac;
|
|
unsigned int polling;
|
|
uint8_t forward_jump, ogen;
|
|
|
|
/*
|
|
* Pick the next timehand, copy current ffclock estimates and move tick
|
|
* times and counter forward.
|
|
*/
|
|
forward_jump = 0;
|
|
ffth = fftimehands->next;
|
|
ogen = ffth->gen;
|
|
ffth->gen = 0;
|
|
cest = &ffth->cest;
|
|
bcopy(&fftimehands->cest, cest, sizeof(struct ffclock_estimate));
|
|
ffdelta = (ffcounter)delta;
|
|
ffth->period_lerp = fftimehands->period_lerp;
|
|
|
|
ffth->tick_time = fftimehands->tick_time;
|
|
ffclock_convert_delta(ffdelta, cest->period, &bt);
|
|
bintime_add(&ffth->tick_time, &bt);
|
|
|
|
ffth->tick_time_lerp = fftimehands->tick_time_lerp;
|
|
ffclock_convert_delta(ffdelta, ffth->period_lerp, &bt);
|
|
bintime_add(&ffth->tick_time_lerp, &bt);
|
|
|
|
ffth->tick_ffcount = fftimehands->tick_ffcount + ffdelta;
|
|
|
|
/*
|
|
* Assess the status of the clock, if the last update is too old, it is
|
|
* likely the synchronisation daemon is dead and the clock is free
|
|
* running.
|
|
*/
|
|
if (ffclock_updated == 0) {
|
|
ffdelta = ffth->tick_ffcount - cest->update_ffcount;
|
|
ffclock_convert_delta(ffdelta, cest->period, &bt);
|
|
if (bt.sec > 2 * FFCLOCK_SKM_SCALE)
|
|
ffclock_status |= FFCLOCK_STA_UNSYNC;
|
|
}
|
|
|
|
/*
|
|
* If available, grab updated clock estimates and make them current.
|
|
* Recompute time at this tick using the updated estimates. The clock
|
|
* estimates passed the feed-forward synchronisation daemon may result
|
|
* in time conversion that is not monotonically increasing (just after
|
|
* the update). time_lerp is a particular linear interpolation over the
|
|
* synchronisation algo polling period that ensures monotonicity for the
|
|
* clock ids requesting it.
|
|
*/
|
|
if (ffclock_updated > 0) {
|
|
bcopy(&ffclock_estimate, cest, sizeof(struct ffclock_estimate));
|
|
ffdelta = ffth->tick_ffcount - cest->update_ffcount;
|
|
ffth->tick_time = cest->update_time;
|
|
ffclock_convert_delta(ffdelta, cest->period, &bt);
|
|
bintime_add(&ffth->tick_time, &bt);
|
|
|
|
/* ffclock_reset sets ffclock_updated to INT8_MAX */
|
|
if (ffclock_updated == INT8_MAX)
|
|
ffth->tick_time_lerp = ffth->tick_time;
|
|
|
|
if (bintime_cmp(&ffth->tick_time, &ffth->tick_time_lerp, >))
|
|
forward_jump = 1;
|
|
else
|
|
forward_jump = 0;
|
|
|
|
bintime_clear(&gap_lerp);
|
|
if (forward_jump) {
|
|
gap_lerp = ffth->tick_time;
|
|
bintime_sub(&gap_lerp, &ffth->tick_time_lerp);
|
|
} else {
|
|
gap_lerp = ffth->tick_time_lerp;
|
|
bintime_sub(&gap_lerp, &ffth->tick_time);
|
|
}
|
|
|
|
/*
|
|
* The reset from the RTC clock may be far from accurate, and
|
|
* reducing the gap between real time and interpolated time
|
|
* could take a very long time if the interpolated clock insists
|
|
* on strict monotonicity. The clock is reset under very strict
|
|
* conditions (kernel time is known to be wrong and
|
|
* synchronization daemon has been restarted recently.
|
|
* ffclock_boottime absorbs the jump to ensure boot time is
|
|
* correct and uptime functions stay consistent.
|
|
*/
|
|
if (((ffclock_status & FFCLOCK_STA_UNSYNC) == FFCLOCK_STA_UNSYNC) &&
|
|
((cest->status & FFCLOCK_STA_UNSYNC) == 0) &&
|
|
((cest->status & FFCLOCK_STA_WARMUP) == FFCLOCK_STA_WARMUP)) {
|
|
if (forward_jump)
|
|
bintime_add(&ffclock_boottime, &gap_lerp);
|
|
else
|
|
bintime_sub(&ffclock_boottime, &gap_lerp);
|
|
ffth->tick_time_lerp = ffth->tick_time;
|
|
bintime_clear(&gap_lerp);
|
|
}
|
|
|
|
ffclock_status = cest->status;
|
|
ffth->period_lerp = cest->period;
|
|
|
|
/*
|
|
* Compute corrected period used for the linear interpolation of
|
|
* time. The rate of linear interpolation is capped to 5000PPM
|
|
* (5ms/s).
|
|
*/
|
|
if (bintime_isset(&gap_lerp)) {
|
|
ffdelta = cest->update_ffcount;
|
|
ffdelta -= fftimehands->cest.update_ffcount;
|
|
ffclock_convert_delta(ffdelta, cest->period, &bt);
|
|
polling = bt.sec;
|
|
bt.sec = 0;
|
|
bt.frac = 5000000 * (uint64_t)18446744073LL;
|
|
bintime_mul(&bt, polling);
|
|
if (bintime_cmp(&gap_lerp, &bt, >))
|
|
gap_lerp = bt;
|
|
|
|
/* Approximate 1 sec by 1-(1/2^64) to ease arithmetic */
|
|
frac = 0;
|
|
if (gap_lerp.sec > 0) {
|
|
frac -= 1;
|
|
frac /= ffdelta / gap_lerp.sec;
|
|
}
|
|
frac += gap_lerp.frac / ffdelta;
|
|
|
|
if (forward_jump)
|
|
ffth->period_lerp += frac;
|
|
else
|
|
ffth->period_lerp -= frac;
|
|
}
|
|
|
|
ffclock_updated = 0;
|
|
}
|
|
if (++ogen == 0)
|
|
ogen = 1;
|
|
ffth->gen = ogen;
|
|
fftimehands = ffth;
|
|
}
|
|
|
|
/*
|
|
* Adjust the fftimehands when the timecounter is changed. Stating the obvious,
|
|
* the old and new hardware counter cannot be read simultaneously. tc_windup()
|
|
* does read the two counters 'back to back', but a few cycles are effectively
|
|
* lost, and not accumulated in tick_ffcount. This is a fairly radical
|
|
* operation for a feed-forward synchronization daemon, and it is its job to not
|
|
* pushing irrelevant data to the kernel. Because there is no locking here,
|
|
* simply force to ignore pending or next update to give daemon a chance to
|
|
* realize the counter has changed.
|
|
*/
|
|
static void
|
|
ffclock_change_tc(struct timehands *th)
|
|
{
|
|
struct fftimehands *ffth;
|
|
struct ffclock_estimate *cest;
|
|
struct timecounter *tc;
|
|
uint8_t ogen;
|
|
|
|
tc = th->th_counter;
|
|
ffth = fftimehands->next;
|
|
ogen = ffth->gen;
|
|
ffth->gen = 0;
|
|
|
|
cest = &ffth->cest;
|
|
bcopy(&(fftimehands->cest), cest, sizeof(struct ffclock_estimate));
|
|
cest->period = ((1ULL << 63) / tc->tc_frequency ) << 1;
|
|
cest->errb_abs = 0;
|
|
cest->errb_rate = 0;
|
|
cest->status |= FFCLOCK_STA_UNSYNC;
|
|
|
|
ffth->tick_ffcount = fftimehands->tick_ffcount;
|
|
ffth->tick_time_lerp = fftimehands->tick_time_lerp;
|
|
ffth->tick_time = fftimehands->tick_time;
|
|
ffth->period_lerp = cest->period;
|
|
|
|
/* Do not lock but ignore next update from synchronization daemon. */
|
|
ffclock_updated--;
|
|
|
|
if (++ogen == 0)
|
|
ogen = 1;
|
|
ffth->gen = ogen;
|
|
fftimehands = ffth;
|
|
}
|
|
|
|
/*
|
|
* Retrieve feed-forward counter and time of last kernel tick.
|
|
*/
|
|
void
|
|
ffclock_last_tick(ffcounter *ffcount, struct bintime *bt, uint32_t flags)
|
|
{
|
|
struct fftimehands *ffth;
|
|
uint8_t gen;
|
|
|
|
/*
|
|
* No locking but check generation has not changed. Also need to make
|
|
* sure ffdelta is positive, i.e. ffcount > tick_ffcount.
|
|
*/
|
|
do {
|
|
ffth = fftimehands;
|
|
gen = ffth->gen;
|
|
if ((flags & FFCLOCK_LERP) == FFCLOCK_LERP)
|
|
*bt = ffth->tick_time_lerp;
|
|
else
|
|
*bt = ffth->tick_time;
|
|
*ffcount = ffth->tick_ffcount;
|
|
} while (gen == 0 || gen != ffth->gen);
|
|
}
|
|
|
|
/*
|
|
* Absolute clock conversion. Low level function to convert ffcounter to
|
|
* bintime. The ffcounter is converted using the current ffclock period estimate
|
|
* or the "interpolated period" to ensure monotonicity.
|
|
* NOTE: this conversion may have been deferred, and the clock updated since the
|
|
* hardware counter has been read.
|
|
*/
|
|
void
|
|
ffclock_convert_abs(ffcounter ffcount, struct bintime *bt, uint32_t flags)
|
|
{
|
|
struct fftimehands *ffth;
|
|
struct bintime bt2;
|
|
ffcounter ffdelta;
|
|
uint8_t gen;
|
|
|
|
/*
|
|
* No locking but check generation has not changed. Also need to make
|
|
* sure ffdelta is positive, i.e. ffcount > tick_ffcount.
|
|
*/
|
|
do {
|
|
ffth = fftimehands;
|
|
gen = ffth->gen;
|
|
if (ffcount > ffth->tick_ffcount)
|
|
ffdelta = ffcount - ffth->tick_ffcount;
|
|
else
|
|
ffdelta = ffth->tick_ffcount - ffcount;
|
|
|
|
if ((flags & FFCLOCK_LERP) == FFCLOCK_LERP) {
|
|
*bt = ffth->tick_time_lerp;
|
|
ffclock_convert_delta(ffdelta, ffth->period_lerp, &bt2);
|
|
} else {
|
|
*bt = ffth->tick_time;
|
|
ffclock_convert_delta(ffdelta, ffth->cest.period, &bt2);
|
|
}
|
|
|
|
if (ffcount > ffth->tick_ffcount)
|
|
bintime_add(bt, &bt2);
|
|
else
|
|
bintime_sub(bt, &bt2);
|
|
} while (gen == 0 || gen != ffth->gen);
|
|
}
|
|
|
|
/*
|
|
* Difference clock conversion.
|
|
* Low level function to Convert a time interval measured in RAW counter units
|
|
* into bintime. The difference clock allows measuring small intervals much more
|
|
* reliably than the absolute clock.
|
|
*/
|
|
void
|
|
ffclock_convert_diff(ffcounter ffdelta, struct bintime *bt)
|
|
{
|
|
struct fftimehands *ffth;
|
|
uint8_t gen;
|
|
|
|
/* No locking but check generation has not changed. */
|
|
do {
|
|
ffth = fftimehands;
|
|
gen = ffth->gen;
|
|
ffclock_convert_delta(ffdelta, ffth->cest.period, bt);
|
|
} while (gen == 0 || gen != ffth->gen);
|
|
}
|
|
|
|
/*
|
|
* Access to current ffcounter value.
|
|
*/
|
|
void
|
|
ffclock_read_counter(ffcounter *ffcount)
|
|
{
|
|
struct timehands *th;
|
|
struct fftimehands *ffth;
|
|
unsigned int gen, delta;
|
|
|
|
/*
|
|
* ffclock_windup() called from tc_windup(), safe to rely on
|
|
* th->th_generation only, for correct delta and ffcounter.
|
|
*/
|
|
do {
|
|
th = timehands;
|
|
gen = atomic_load_acq_int(&th->th_generation);
|
|
ffth = fftimehands;
|
|
delta = tc_delta(th);
|
|
*ffcount = ffth->tick_ffcount;
|
|
atomic_thread_fence_acq();
|
|
} while (gen == 0 || gen != th->th_generation);
|
|
|
|
*ffcount += delta;
|
|
}
|
|
|
|
void
|
|
binuptime(struct bintime *bt)
|
|
{
|
|
|
|
binuptime_fromclock(bt, sysclock_active);
|
|
}
|
|
|
|
void
|
|
nanouptime(struct timespec *tsp)
|
|
{
|
|
|
|
nanouptime_fromclock(tsp, sysclock_active);
|
|
}
|
|
|
|
void
|
|
microuptime(struct timeval *tvp)
|
|
{
|
|
|
|
microuptime_fromclock(tvp, sysclock_active);
|
|
}
|
|
|
|
void
|
|
bintime(struct bintime *bt)
|
|
{
|
|
|
|
bintime_fromclock(bt, sysclock_active);
|
|
}
|
|
|
|
void
|
|
nanotime(struct timespec *tsp)
|
|
{
|
|
|
|
nanotime_fromclock(tsp, sysclock_active);
|
|
}
|
|
|
|
void
|
|
microtime(struct timeval *tvp)
|
|
{
|
|
|
|
microtime_fromclock(tvp, sysclock_active);
|
|
}
|
|
|
|
void
|
|
getbinuptime(struct bintime *bt)
|
|
{
|
|
|
|
getbinuptime_fromclock(bt, sysclock_active);
|
|
}
|
|
|
|
void
|
|
getnanouptime(struct timespec *tsp)
|
|
{
|
|
|
|
getnanouptime_fromclock(tsp, sysclock_active);
|
|
}
|
|
|
|
void
|
|
getmicrouptime(struct timeval *tvp)
|
|
{
|
|
|
|
getmicrouptime_fromclock(tvp, sysclock_active);
|
|
}
|
|
|
|
void
|
|
getbintime(struct bintime *bt)
|
|
{
|
|
|
|
getbintime_fromclock(bt, sysclock_active);
|
|
}
|
|
|
|
void
|
|
getnanotime(struct timespec *tsp)
|
|
{
|
|
|
|
getnanotime_fromclock(tsp, sysclock_active);
|
|
}
|
|
|
|
void
|
|
getmicrotime(struct timeval *tvp)
|
|
{
|
|
|
|
getmicrouptime_fromclock(tvp, sysclock_active);
|
|
}
|
|
|
|
#endif /* FFCLOCK */
|
|
|
|
/*
|
|
* This is a clone of getnanotime and used for walltimestamps.
|
|
* The dtrace_ prefix prevents fbt from creating probes for
|
|
* it so walltimestamp can be safely used in all fbt probes.
|
|
*/
|
|
void
|
|
dtrace_getnanotime(struct timespec *tsp)
|
|
{
|
|
|
|
GETTHMEMBER(tsp, th_nanotime);
|
|
}
|
|
|
|
/*
|
|
* This is a clone of getnanouptime used for time since boot.
|
|
* The dtrace_ prefix prevents fbt from creating probes for
|
|
* it so an uptime that can be safely used in all fbt probes.
|
|
*/
|
|
void
|
|
dtrace_getnanouptime(struct timespec *tsp)
|
|
{
|
|
struct bintime bt;
|
|
|
|
GETTHMEMBER(&bt, th_offset);
|
|
bintime2timespec(&bt, tsp);
|
|
}
|
|
|
|
/*
|
|
* System clock currently providing time to the system. Modifiable via sysctl
|
|
* when the FFCLOCK option is defined.
|
|
*/
|
|
int sysclock_active = SYSCLOCK_FBCK;
|
|
|
|
/* Internal NTP status and error estimates. */
|
|
extern int time_status;
|
|
extern long time_esterror;
|
|
|
|
/*
|
|
* Take a snapshot of sysclock data which can be used to compare system clocks
|
|
* and generate timestamps after the fact.
|
|
*/
|
|
void
|
|
sysclock_getsnapshot(struct sysclock_snap *clock_snap, int fast)
|
|
{
|
|
struct fbclock_info *fbi;
|
|
struct timehands *th;
|
|
struct bintime bt;
|
|
unsigned int delta, gen;
|
|
#ifdef FFCLOCK
|
|
ffcounter ffcount;
|
|
struct fftimehands *ffth;
|
|
struct ffclock_info *ffi;
|
|
struct ffclock_estimate cest;
|
|
|
|
ffi = &clock_snap->ff_info;
|
|
#endif
|
|
|
|
fbi = &clock_snap->fb_info;
|
|
delta = 0;
|
|
|
|
do {
|
|
th = timehands;
|
|
gen = atomic_load_acq_int(&th->th_generation);
|
|
fbi->th_scale = th->th_scale;
|
|
fbi->tick_time = th->th_offset;
|
|
#ifdef FFCLOCK
|
|
ffth = fftimehands;
|
|
ffi->tick_time = ffth->tick_time_lerp;
|
|
ffi->tick_time_lerp = ffth->tick_time_lerp;
|
|
ffi->period = ffth->cest.period;
|
|
ffi->period_lerp = ffth->period_lerp;
|
|
clock_snap->ffcount = ffth->tick_ffcount;
|
|
cest = ffth->cest;
|
|
#endif
|
|
if (!fast)
|
|
delta = tc_delta(th);
|
|
atomic_thread_fence_acq();
|
|
} while (gen == 0 || gen != th->th_generation);
|
|
|
|
clock_snap->delta = delta;
|
|
clock_snap->sysclock_active = sysclock_active;
|
|
|
|
/* Record feedback clock status and error. */
|
|
clock_snap->fb_info.status = time_status;
|
|
/* XXX: Very crude estimate of feedback clock error. */
|
|
bt.sec = time_esterror / 1000000;
|
|
bt.frac = ((time_esterror - bt.sec) * 1000000) *
|
|
(uint64_t)18446744073709ULL;
|
|
clock_snap->fb_info.error = bt;
|
|
|
|
#ifdef FFCLOCK
|
|
if (!fast)
|
|
clock_snap->ffcount += delta;
|
|
|
|
/* Record feed-forward clock leap second adjustment. */
|
|
ffi->leapsec_adjustment = cest.leapsec_total;
|
|
if (clock_snap->ffcount > cest.leapsec_next)
|
|
ffi->leapsec_adjustment -= cest.leapsec;
|
|
|
|
/* Record feed-forward clock status and error. */
|
|
clock_snap->ff_info.status = cest.status;
|
|
ffcount = clock_snap->ffcount - cest.update_ffcount;
|
|
ffclock_convert_delta(ffcount, cest.period, &bt);
|
|
/* 18446744073709 = int(2^64/1e12), err_bound_rate in [ps/s]. */
|
|
bintime_mul(&bt, cest.errb_rate * (uint64_t)18446744073709ULL);
|
|
/* 18446744073 = int(2^64 / 1e9), since err_abs in [ns]. */
|
|
bintime_addx(&bt, cest.errb_abs * (uint64_t)18446744073ULL);
|
|
clock_snap->ff_info.error = bt;
|
|
#endif
|
|
}
|
|
|
|
/*
|
|
* Convert a sysclock snapshot into a struct bintime based on the specified
|
|
* clock source and flags.
|
|
*/
|
|
int
|
|
sysclock_snap2bintime(struct sysclock_snap *cs, struct bintime *bt,
|
|
int whichclock, uint32_t flags)
|
|
{
|
|
struct bintime boottimebin;
|
|
#ifdef FFCLOCK
|
|
struct bintime bt2;
|
|
uint64_t period;
|
|
#endif
|
|
|
|
switch (whichclock) {
|
|
case SYSCLOCK_FBCK:
|
|
*bt = cs->fb_info.tick_time;
|
|
|
|
/* If snapshot was created with !fast, delta will be >0. */
|
|
if (cs->delta > 0)
|
|
bintime_addx(bt, cs->fb_info.th_scale * cs->delta);
|
|
|
|
if ((flags & FBCLOCK_UPTIME) == 0) {
|
|
getboottimebin(&boottimebin);
|
|
bintime_add(bt, &boottimebin);
|
|
}
|
|
break;
|
|
#ifdef FFCLOCK
|
|
case SYSCLOCK_FFWD:
|
|
if (flags & FFCLOCK_LERP) {
|
|
*bt = cs->ff_info.tick_time_lerp;
|
|
period = cs->ff_info.period_lerp;
|
|
} else {
|
|
*bt = cs->ff_info.tick_time;
|
|
period = cs->ff_info.period;
|
|
}
|
|
|
|
/* If snapshot was created with !fast, delta will be >0. */
|
|
if (cs->delta > 0) {
|
|
ffclock_convert_delta(cs->delta, period, &bt2);
|
|
bintime_add(bt, &bt2);
|
|
}
|
|
|
|
/* Leap second adjustment. */
|
|
if (flags & FFCLOCK_LEAPSEC)
|
|
bt->sec -= cs->ff_info.leapsec_adjustment;
|
|
|
|
/* Boot time adjustment, for uptime/monotonic clocks. */
|
|
if (flags & FFCLOCK_UPTIME)
|
|
bintime_sub(bt, &ffclock_boottime);
|
|
break;
|
|
#endif
|
|
default:
|
|
return (EINVAL);
|
|
break;
|
|
}
|
|
|
|
return (0);
|
|
}
|
|
|
|
/*
|
|
* Initialize a new timecounter and possibly use it.
|
|
*/
|
|
void
|
|
tc_init(struct timecounter *tc)
|
|
{
|
|
u_int u;
|
|
struct sysctl_oid *tc_root;
|
|
|
|
u = tc->tc_frequency / tc->tc_counter_mask;
|
|
/* XXX: We need some margin here, 10% is a guess */
|
|
u *= 11;
|
|
u /= 10;
|
|
if (u > hz && tc->tc_quality >= 0) {
|
|
tc->tc_quality = -2000;
|
|
if (bootverbose) {
|
|
printf("Timecounter \"%s\" frequency %ju Hz",
|
|
tc->tc_name, (uintmax_t)tc->tc_frequency);
|
|
printf(" -- Insufficient hz, needs at least %u\n", u);
|
|
}
|
|
} else if (tc->tc_quality >= 0 || bootverbose) {
|
|
printf("Timecounter \"%s\" frequency %ju Hz quality %d\n",
|
|
tc->tc_name, (uintmax_t)tc->tc_frequency,
|
|
tc->tc_quality);
|
|
}
|
|
|
|
/*
|
|
* Set up sysctl tree for this counter.
|
|
*/
|
|
tc_root = SYSCTL_ADD_NODE_WITH_LABEL(NULL,
|
|
SYSCTL_STATIC_CHILDREN(_kern_timecounter_tc), OID_AUTO, tc->tc_name,
|
|
CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
|
|
"timecounter description", "timecounter");
|
|
SYSCTL_ADD_UINT(NULL, SYSCTL_CHILDREN(tc_root), OID_AUTO,
|
|
"mask", CTLFLAG_RD, &(tc->tc_counter_mask), 0,
|
|
"mask for implemented bits");
|
|
SYSCTL_ADD_PROC(NULL, SYSCTL_CHILDREN(tc_root), OID_AUTO,
|
|
"counter", CTLTYPE_UINT | CTLFLAG_RD | CTLFLAG_MPSAFE, tc,
|
|
sizeof(*tc), sysctl_kern_timecounter_get, "IU",
|
|
"current timecounter value");
|
|
SYSCTL_ADD_PROC(NULL, SYSCTL_CHILDREN(tc_root), OID_AUTO,
|
|
"frequency", CTLTYPE_U64 | CTLFLAG_RD | CTLFLAG_MPSAFE, tc,
|
|
sizeof(*tc), sysctl_kern_timecounter_freq, "QU",
|
|
"timecounter frequency");
|
|
SYSCTL_ADD_INT(NULL, SYSCTL_CHILDREN(tc_root), OID_AUTO,
|
|
"quality", CTLFLAG_RD, &(tc->tc_quality), 0,
|
|
"goodness of time counter");
|
|
|
|
mtx_lock(&tc_lock);
|
|
tc->tc_next = timecounters;
|
|
timecounters = tc;
|
|
|
|
/*
|
|
* Do not automatically switch if the current tc was specifically
|
|
* chosen. Never automatically use a timecounter with negative quality.
|
|
* Even though we run on the dummy counter, switching here may be
|
|
* worse since this timecounter may not be monotonic.
|
|
*/
|
|
if (tc_chosen)
|
|
goto unlock;
|
|
if (tc->tc_quality < 0)
|
|
goto unlock;
|
|
if (tc_from_tunable[0] != '\0' &&
|
|
strcmp(tc->tc_name, tc_from_tunable) == 0) {
|
|
tc_chosen = 1;
|
|
tc_from_tunable[0] = '\0';
|
|
} else {
|
|
if (tc->tc_quality < timecounter->tc_quality)
|
|
goto unlock;
|
|
if (tc->tc_quality == timecounter->tc_quality &&
|
|
tc->tc_frequency < timecounter->tc_frequency)
|
|
goto unlock;
|
|
}
|
|
(void)tc->tc_get_timecount(tc);
|
|
timecounter = tc;
|
|
unlock:
|
|
mtx_unlock(&tc_lock);
|
|
}
|
|
|
|
/* Report the frequency of the current timecounter. */
|
|
uint64_t
|
|
tc_getfrequency(void)
|
|
{
|
|
|
|
return (timehands->th_counter->tc_frequency);
|
|
}
|
|
|
|
static bool
|
|
sleeping_on_old_rtc(struct thread *td)
|
|
{
|
|
|
|
/*
|
|
* td_rtcgen is modified by curthread when it is running,
|
|
* and by other threads in this function. By finding the thread
|
|
* on a sleepqueue and holding the lock on the sleepqueue
|
|
* chain, we guarantee that the thread is not running and that
|
|
* modifying td_rtcgen is safe. Setting td_rtcgen to zero informs
|
|
* the thread that it was woken due to a real-time clock adjustment.
|
|
* (The declaration of td_rtcgen refers to this comment.)
|
|
*/
|
|
if (td->td_rtcgen != 0 && td->td_rtcgen != rtc_generation) {
|
|
td->td_rtcgen = 0;
|
|
return (true);
|
|
}
|
|
return (false);
|
|
}
|
|
|
|
static struct mtx tc_setclock_mtx;
|
|
MTX_SYSINIT(tc_setclock_init, &tc_setclock_mtx, "tcsetc", MTX_SPIN);
|
|
|
|
/*
|
|
* Step our concept of UTC. This is done by modifying our estimate of
|
|
* when we booted.
|
|
*/
|
|
void
|
|
tc_setclock(struct timespec *ts)
|
|
{
|
|
struct timespec tbef, taft;
|
|
struct bintime bt, bt2;
|
|
|
|
timespec2bintime(ts, &bt);
|
|
nanotime(&tbef);
|
|
mtx_lock_spin(&tc_setclock_mtx);
|
|
cpu_tick_calibrate(1);
|
|
binuptime(&bt2);
|
|
bintime_sub(&bt, &bt2);
|
|
|
|
/* XXX fiddle all the little crinkly bits around the fiords... */
|
|
tc_windup(&bt);
|
|
mtx_unlock_spin(&tc_setclock_mtx);
|
|
|
|
/* Avoid rtc_generation == 0, since td_rtcgen == 0 is special. */
|
|
atomic_add_rel_int(&rtc_generation, 2);
|
|
sleepq_chains_remove_matching(sleeping_on_old_rtc);
|
|
if (timestepwarnings) {
|
|
nanotime(&taft);
|
|
log(LOG_INFO,
|
|
"Time stepped from %jd.%09ld to %jd.%09ld (%jd.%09ld)\n",
|
|
(intmax_t)tbef.tv_sec, tbef.tv_nsec,
|
|
(intmax_t)taft.tv_sec, taft.tv_nsec,
|
|
(intmax_t)ts->tv_sec, ts->tv_nsec);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Recalculate the scaling factor. We want the number of 1/2^64
|
|
* fractions of a second per period of the hardware counter, taking
|
|
* into account the th_adjustment factor which the NTP PLL/adjtime(2)
|
|
* processing provides us with.
|
|
*
|
|
* The th_adjustment is nanoseconds per second with 32 bit binary
|
|
* fraction and we want 64 bit binary fraction of second:
|
|
*
|
|
* x = a * 2^32 / 10^9 = a * 4.294967296
|
|
*
|
|
* The range of th_adjustment is +/- 5000PPM so inside a 64bit int
|
|
* we can only multiply by about 850 without overflowing, that
|
|
* leaves no suitably precise fractions for multiply before divide.
|
|
*
|
|
* Divide before multiply with a fraction of 2199/512 results in a
|
|
* systematic undercompensation of 10PPM of th_adjustment. On a
|
|
* 5000PPM adjustment this is a 0.05PPM error. This is acceptable.
|
|
*
|
|
* We happily sacrifice the lowest of the 64 bits of our result
|
|
* to the goddess of code clarity.
|
|
*/
|
|
static void
|
|
recalculate_scaling_factor_and_large_delta(struct timehands *th)
|
|
{
|
|
uint64_t scale;
|
|
|
|
scale = (uint64_t)1 << 63;
|
|
scale += (th->th_adjustment / 1024) * 2199;
|
|
scale /= th->th_counter->tc_frequency;
|
|
th->th_scale = scale * 2;
|
|
th->th_large_delta = MIN(((uint64_t)1 << 63) / scale, UINT_MAX);
|
|
}
|
|
|
|
/*
|
|
* Initialize the next struct timehands in the ring and make
|
|
* it the active timehands. Along the way we might switch to a different
|
|
* timecounter and/or do seconds processing in NTP. Slightly magic.
|
|
*/
|
|
static void
|
|
tc_windup(struct bintime *new_boottimebin)
|
|
{
|
|
struct bintime bt;
|
|
struct timecounter *tc;
|
|
struct timehands *th, *tho;
|
|
u_int delta, ncount, ogen;
|
|
int i;
|
|
time_t t;
|
|
|
|
/*
|
|
* Make the next timehands a copy of the current one, but do
|
|
* not overwrite the generation or next pointer. While we
|
|
* update the contents, the generation must be zero. We need
|
|
* to ensure that the zero generation is visible before the
|
|
* data updates become visible, which requires release fence.
|
|
* For similar reasons, re-reading of the generation after the
|
|
* data is read should use acquire fence.
|
|
*/
|
|
tho = timehands;
|
|
th = tho->th_next;
|
|
ogen = th->th_generation;
|
|
th->th_generation = 0;
|
|
atomic_thread_fence_rel();
|
|
memcpy(th, tho, offsetof(struct timehands, th_generation));
|
|
if (new_boottimebin != NULL)
|
|
th->th_boottime = *new_boottimebin;
|
|
|
|
/*
|
|
* Capture a timecounter delta on the current timecounter and if
|
|
* changing timecounters, a counter value from the new timecounter.
|
|
* Update the offset fields accordingly.
|
|
*/
|
|
tc = atomic_load_ptr(&timecounter);
|
|
delta = tc_delta(th);
|
|
if (th->th_counter != tc)
|
|
ncount = tc->tc_get_timecount(tc);
|
|
else
|
|
ncount = 0;
|
|
#ifdef FFCLOCK
|
|
ffclock_windup(delta);
|
|
#endif
|
|
th->th_offset_count += delta;
|
|
th->th_offset_count &= th->th_counter->tc_counter_mask;
|
|
bintime_add_tc_delta(&th->th_offset, th->th_scale,
|
|
th->th_large_delta, delta);
|
|
|
|
/*
|
|
* Hardware latching timecounters may not generate interrupts on
|
|
* PPS events, so instead we poll them. There is a finite risk that
|
|
* the hardware might capture a count which is later than the one we
|
|
* got above, and therefore possibly in the next NTP second which might
|
|
* have a different rate than the current NTP second. It doesn't
|
|
* matter in practice.
|
|
*/
|
|
if (tho->th_counter->tc_poll_pps)
|
|
tho->th_counter->tc_poll_pps(tho->th_counter);
|
|
|
|
/*
|
|
* Deal with NTP second processing. The loop normally
|
|
* iterates at most once, but in extreme situations it might
|
|
* keep NTP sane if timeouts are not run for several seconds.
|
|
* At boot, the time step can be large when the TOD hardware
|
|
* has been read, so on really large steps, we call
|
|
* ntp_update_second only twice. We need to call it twice in
|
|
* case we missed a leap second.
|
|
*/
|
|
bt = th->th_offset;
|
|
bintime_add(&bt, &th->th_boottime);
|
|
i = bt.sec - tho->th_microtime.tv_sec;
|
|
if (i > 0) {
|
|
if (i > LARGE_STEP)
|
|
i = 2;
|
|
|
|
do {
|
|
t = bt.sec;
|
|
ntp_update_second(&th->th_adjustment, &bt.sec);
|
|
if (bt.sec != t)
|
|
th->th_boottime.sec += bt.sec - t;
|
|
--i;
|
|
} while (i > 0);
|
|
|
|
recalculate_scaling_factor_and_large_delta(th);
|
|
}
|
|
|
|
/* Update the UTC timestamps used by the get*() functions. */
|
|
th->th_bintime = bt;
|
|
bintime2timeval(&bt, &th->th_microtime);
|
|
bintime2timespec(&bt, &th->th_nanotime);
|
|
|
|
/* Now is a good time to change timecounters. */
|
|
if (th->th_counter != tc) {
|
|
#ifndef __arm__
|
|
if ((tc->tc_flags & TC_FLAGS_C2STOP) != 0)
|
|
cpu_disable_c2_sleep++;
|
|
if ((th->th_counter->tc_flags & TC_FLAGS_C2STOP) != 0)
|
|
cpu_disable_c2_sleep--;
|
|
#endif
|
|
th->th_counter = tc;
|
|
th->th_offset_count = ncount;
|
|
tc_min_ticktock_freq = max(1, tc->tc_frequency /
|
|
(((uint64_t)tc->tc_counter_mask + 1) / 3));
|
|
recalculate_scaling_factor_and_large_delta(th);
|
|
#ifdef FFCLOCK
|
|
ffclock_change_tc(th);
|
|
#endif
|
|
}
|
|
|
|
/*
|
|
* Now that the struct timehands is again consistent, set the new
|
|
* generation number, making sure to not make it zero.
|
|
*/
|
|
if (++ogen == 0)
|
|
ogen = 1;
|
|
atomic_store_rel_int(&th->th_generation, ogen);
|
|
|
|
/* Go live with the new struct timehands. */
|
|
#ifdef FFCLOCK
|
|
switch (sysclock_active) {
|
|
case SYSCLOCK_FBCK:
|
|
#endif
|
|
time_second = th->th_microtime.tv_sec;
|
|
time_uptime = th->th_offset.sec;
|
|
#ifdef FFCLOCK
|
|
break;
|
|
case SYSCLOCK_FFWD:
|
|
time_second = fftimehands->tick_time_lerp.sec;
|
|
time_uptime = fftimehands->tick_time_lerp.sec - ffclock_boottime.sec;
|
|
break;
|
|
}
|
|
#endif
|
|
|
|
timehands = th;
|
|
timekeep_push_vdso();
|
|
}
|
|
|
|
/* Report or change the active timecounter hardware. */
|
|
static int
|
|
sysctl_kern_timecounter_hardware(SYSCTL_HANDLER_ARGS)
|
|
{
|
|
char newname[32];
|
|
struct timecounter *newtc, *tc;
|
|
int error;
|
|
|
|
mtx_lock(&tc_lock);
|
|
tc = timecounter;
|
|
strlcpy(newname, tc->tc_name, sizeof(newname));
|
|
mtx_unlock(&tc_lock);
|
|
|
|
error = sysctl_handle_string(oidp, &newname[0], sizeof(newname), req);
|
|
if (error != 0 || req->newptr == NULL)
|
|
return (error);
|
|
|
|
mtx_lock(&tc_lock);
|
|
/* Record that the tc in use now was specifically chosen. */
|
|
tc_chosen = 1;
|
|
if (strcmp(newname, tc->tc_name) == 0) {
|
|
mtx_unlock(&tc_lock);
|
|
return (0);
|
|
}
|
|
for (newtc = timecounters; newtc != NULL; newtc = newtc->tc_next) {
|
|
if (strcmp(newname, newtc->tc_name) != 0)
|
|
continue;
|
|
|
|
/* Warm up new timecounter. */
|
|
(void)newtc->tc_get_timecount(newtc);
|
|
|
|
timecounter = newtc;
|
|
|
|
/*
|
|
* The vdso timehands update is deferred until the next
|
|
* 'tc_windup()'.
|
|
*
|
|
* This is prudent given that 'timekeep_push_vdso()' does not
|
|
* use any locking and that it can be called in hard interrupt
|
|
* context via 'tc_windup()'.
|
|
*/
|
|
break;
|
|
}
|
|
mtx_unlock(&tc_lock);
|
|
return (newtc != NULL ? 0 : EINVAL);
|
|
}
|
|
SYSCTL_PROC(_kern_timecounter, OID_AUTO, hardware,
|
|
CTLTYPE_STRING | CTLFLAG_RWTUN | CTLFLAG_NOFETCH | CTLFLAG_MPSAFE, 0, 0,
|
|
sysctl_kern_timecounter_hardware, "A",
|
|
"Timecounter hardware selected");
|
|
|
|
/* Report the available timecounter hardware. */
|
|
static int
|
|
sysctl_kern_timecounter_choice(SYSCTL_HANDLER_ARGS)
|
|
{
|
|
struct sbuf sb;
|
|
struct timecounter *tc;
|
|
int error;
|
|
|
|
error = sysctl_wire_old_buffer(req, 0);
|
|
if (error != 0)
|
|
return (error);
|
|
sbuf_new_for_sysctl(&sb, NULL, 0, req);
|
|
mtx_lock(&tc_lock);
|
|
for (tc = timecounters; tc != NULL; tc = tc->tc_next) {
|
|
if (tc != timecounters)
|
|
sbuf_putc(&sb, ' ');
|
|
sbuf_printf(&sb, "%s(%d)", tc->tc_name, tc->tc_quality);
|
|
}
|
|
mtx_unlock(&tc_lock);
|
|
error = sbuf_finish(&sb);
|
|
sbuf_delete(&sb);
|
|
return (error);
|
|
}
|
|
|
|
SYSCTL_PROC(_kern_timecounter, OID_AUTO, choice,
|
|
CTLTYPE_STRING | CTLFLAG_RD | CTLFLAG_MPSAFE, 0, 0,
|
|
sysctl_kern_timecounter_choice, "A",
|
|
"Timecounter hardware detected");
|
|
|
|
/*
|
|
* RFC 2783 PPS-API implementation.
|
|
*/
|
|
|
|
/*
|
|
* Return true if the driver is aware of the abi version extensions in the
|
|
* pps_state structure, and it supports at least the given abi version number.
|
|
*/
|
|
static inline int
|
|
abi_aware(struct pps_state *pps, int vers)
|
|
{
|
|
|
|
return ((pps->kcmode & KCMODE_ABIFLAG) && pps->driver_abi >= vers);
|
|
}
|
|
|
|
static int
|
|
pps_fetch(struct pps_fetch_args *fapi, struct pps_state *pps)
|
|
{
|
|
int err, timo;
|
|
pps_seq_t aseq, cseq;
|
|
struct timeval tv;
|
|
|
|
if (fapi->tsformat && fapi->tsformat != PPS_TSFMT_TSPEC)
|
|
return (EINVAL);
|
|
|
|
/*
|
|
* If no timeout is requested, immediately return whatever values were
|
|
* most recently captured. If timeout seconds is -1, that's a request
|
|
* to block without a timeout. WITNESS won't let us sleep forever
|
|
* without a lock (we really don't need a lock), so just repeatedly
|
|
* sleep a long time.
|
|
*/
|
|
if (fapi->timeout.tv_sec || fapi->timeout.tv_nsec) {
|
|
if (fapi->timeout.tv_sec == -1)
|
|
timo = 0x7fffffff;
|
|
else {
|
|
tv.tv_sec = fapi->timeout.tv_sec;
|
|
tv.tv_usec = fapi->timeout.tv_nsec / 1000;
|
|
timo = tvtohz(&tv);
|
|
}
|
|
aseq = atomic_load_int(&pps->ppsinfo.assert_sequence);
|
|
cseq = atomic_load_int(&pps->ppsinfo.clear_sequence);
|
|
while (aseq == atomic_load_int(&pps->ppsinfo.assert_sequence) &&
|
|
cseq == atomic_load_int(&pps->ppsinfo.clear_sequence)) {
|
|
if (abi_aware(pps, 1) && pps->driver_mtx != NULL) {
|
|
if (pps->flags & PPSFLAG_MTX_SPIN) {
|
|
err = msleep_spin(pps, pps->driver_mtx,
|
|
"ppsfch", timo);
|
|
} else {
|
|
err = msleep(pps, pps->driver_mtx, PCATCH,
|
|
"ppsfch", timo);
|
|
}
|
|
} else {
|
|
err = tsleep(pps, PCATCH, "ppsfch", timo);
|
|
}
|
|
if (err == EWOULDBLOCK) {
|
|
if (fapi->timeout.tv_sec == -1) {
|
|
continue;
|
|
} else {
|
|
return (ETIMEDOUT);
|
|
}
|
|
} else if (err != 0) {
|
|
return (err);
|
|
}
|
|
}
|
|
}
|
|
|
|
pps->ppsinfo.current_mode = pps->ppsparam.mode;
|
|
fapi->pps_info_buf = pps->ppsinfo;
|
|
|
|
return (0);
|
|
}
|
|
|
|
int
|
|
pps_ioctl(u_long cmd, caddr_t data, struct pps_state *pps)
|
|
{
|
|
pps_params_t *app;
|
|
struct pps_fetch_args *fapi;
|
|
#ifdef FFCLOCK
|
|
struct pps_fetch_ffc_args *fapi_ffc;
|
|
#endif
|
|
#ifdef PPS_SYNC
|
|
struct pps_kcbind_args *kapi;
|
|
#endif
|
|
|
|
KASSERT(pps != NULL, ("NULL pps pointer in pps_ioctl"));
|
|
switch (cmd) {
|
|
case PPS_IOC_CREATE:
|
|
return (0);
|
|
case PPS_IOC_DESTROY:
|
|
return (0);
|
|
case PPS_IOC_SETPARAMS:
|
|
app = (pps_params_t *)data;
|
|
if (app->mode & ~pps->ppscap)
|
|
return (EINVAL);
|
|
#ifdef FFCLOCK
|
|
/* Ensure only a single clock is selected for ffc timestamp. */
|
|
if ((app->mode & PPS_TSCLK_MASK) == PPS_TSCLK_MASK)
|
|
return (EINVAL);
|
|
#endif
|
|
pps->ppsparam = *app;
|
|
return (0);
|
|
case PPS_IOC_GETPARAMS:
|
|
app = (pps_params_t *)data;
|
|
*app = pps->ppsparam;
|
|
app->api_version = PPS_API_VERS_1;
|
|
return (0);
|
|
case PPS_IOC_GETCAP:
|
|
*(int*)data = pps->ppscap;
|
|
return (0);
|
|
case PPS_IOC_FETCH:
|
|
fapi = (struct pps_fetch_args *)data;
|
|
return (pps_fetch(fapi, pps));
|
|
#ifdef FFCLOCK
|
|
case PPS_IOC_FETCH_FFCOUNTER:
|
|
fapi_ffc = (struct pps_fetch_ffc_args *)data;
|
|
if (fapi_ffc->tsformat && fapi_ffc->tsformat !=
|
|
PPS_TSFMT_TSPEC)
|
|
return (EINVAL);
|
|
if (fapi_ffc->timeout.tv_sec || fapi_ffc->timeout.tv_nsec)
|
|
return (EOPNOTSUPP);
|
|
pps->ppsinfo_ffc.current_mode = pps->ppsparam.mode;
|
|
fapi_ffc->pps_info_buf_ffc = pps->ppsinfo_ffc;
|
|
/* Overwrite timestamps if feedback clock selected. */
|
|
switch (pps->ppsparam.mode & PPS_TSCLK_MASK) {
|
|
case PPS_TSCLK_FBCK:
|
|
fapi_ffc->pps_info_buf_ffc.assert_timestamp =
|
|
pps->ppsinfo.assert_timestamp;
|
|
fapi_ffc->pps_info_buf_ffc.clear_timestamp =
|
|
pps->ppsinfo.clear_timestamp;
|
|
break;
|
|
case PPS_TSCLK_FFWD:
|
|
break;
|
|
default:
|
|
break;
|
|
}
|
|
return (0);
|
|
#endif /* FFCLOCK */
|
|
case PPS_IOC_KCBIND:
|
|
#ifdef PPS_SYNC
|
|
kapi = (struct pps_kcbind_args *)data;
|
|
/* XXX Only root should be able to do this */
|
|
if (kapi->tsformat && kapi->tsformat != PPS_TSFMT_TSPEC)
|
|
return (EINVAL);
|
|
if (kapi->kernel_consumer != PPS_KC_HARDPPS)
|
|
return (EINVAL);
|
|
if (kapi->edge & ~pps->ppscap)
|
|
return (EINVAL);
|
|
pps->kcmode = (kapi->edge & KCMODE_EDGEMASK) |
|
|
(pps->kcmode & KCMODE_ABIFLAG);
|
|
return (0);
|
|
#else
|
|
return (EOPNOTSUPP);
|
|
#endif
|
|
default:
|
|
return (ENOIOCTL);
|
|
}
|
|
}
|
|
|
|
void
|
|
pps_init(struct pps_state *pps)
|
|
{
|
|
pps->ppscap |= PPS_TSFMT_TSPEC | PPS_CANWAIT;
|
|
if (pps->ppscap & PPS_CAPTUREASSERT)
|
|
pps->ppscap |= PPS_OFFSETASSERT;
|
|
if (pps->ppscap & PPS_CAPTURECLEAR)
|
|
pps->ppscap |= PPS_OFFSETCLEAR;
|
|
#ifdef FFCLOCK
|
|
pps->ppscap |= PPS_TSCLK_MASK;
|
|
#endif
|
|
pps->kcmode &= ~KCMODE_ABIFLAG;
|
|
}
|
|
|
|
void
|
|
pps_init_abi(struct pps_state *pps)
|
|
{
|
|
|
|
pps_init(pps);
|
|
if (pps->driver_abi > 0) {
|
|
pps->kcmode |= KCMODE_ABIFLAG;
|
|
pps->kernel_abi = PPS_ABI_VERSION;
|
|
}
|
|
}
|
|
|
|
void
|
|
pps_capture(struct pps_state *pps)
|
|
{
|
|
struct timehands *th;
|
|
|
|
KASSERT(pps != NULL, ("NULL pps pointer in pps_capture"));
|
|
th = timehands;
|
|
pps->capgen = atomic_load_acq_int(&th->th_generation);
|
|
pps->capth = th;
|
|
#ifdef FFCLOCK
|
|
pps->capffth = fftimehands;
|
|
#endif
|
|
pps->capcount = th->th_counter->tc_get_timecount(th->th_counter);
|
|
atomic_thread_fence_acq();
|
|
if (pps->capgen != th->th_generation)
|
|
pps->capgen = 0;
|
|
}
|
|
|
|
void
|
|
pps_event(struct pps_state *pps, int event)
|
|
{
|
|
struct bintime bt;
|
|
struct timespec ts, *tsp, *osp;
|
|
u_int tcount, *pcount;
|
|
int foff;
|
|
pps_seq_t *pseq;
|
|
#ifdef FFCLOCK
|
|
struct timespec *tsp_ffc;
|
|
pps_seq_t *pseq_ffc;
|
|
ffcounter *ffcount;
|
|
#endif
|
|
#ifdef PPS_SYNC
|
|
int fhard;
|
|
#endif
|
|
|
|
KASSERT(pps != NULL, ("NULL pps pointer in pps_event"));
|
|
/* Nothing to do if not currently set to capture this event type. */
|
|
if ((event & pps->ppsparam.mode) == 0)
|
|
return;
|
|
/* If the timecounter was wound up underneath us, bail out. */
|
|
if (pps->capgen == 0 || pps->capgen !=
|
|
atomic_load_acq_int(&pps->capth->th_generation))
|
|
return;
|
|
|
|
/* Things would be easier with arrays. */
|
|
if (event == PPS_CAPTUREASSERT) {
|
|
tsp = &pps->ppsinfo.assert_timestamp;
|
|
osp = &pps->ppsparam.assert_offset;
|
|
foff = pps->ppsparam.mode & PPS_OFFSETASSERT;
|
|
#ifdef PPS_SYNC
|
|
fhard = pps->kcmode & PPS_CAPTUREASSERT;
|
|
#endif
|
|
pcount = &pps->ppscount[0];
|
|
pseq = &pps->ppsinfo.assert_sequence;
|
|
#ifdef FFCLOCK
|
|
ffcount = &pps->ppsinfo_ffc.assert_ffcount;
|
|
tsp_ffc = &pps->ppsinfo_ffc.assert_timestamp;
|
|
pseq_ffc = &pps->ppsinfo_ffc.assert_sequence;
|
|
#endif
|
|
} else {
|
|
tsp = &pps->ppsinfo.clear_timestamp;
|
|
osp = &pps->ppsparam.clear_offset;
|
|
foff = pps->ppsparam.mode & PPS_OFFSETCLEAR;
|
|
#ifdef PPS_SYNC
|
|
fhard = pps->kcmode & PPS_CAPTURECLEAR;
|
|
#endif
|
|
pcount = &pps->ppscount[1];
|
|
pseq = &pps->ppsinfo.clear_sequence;
|
|
#ifdef FFCLOCK
|
|
ffcount = &pps->ppsinfo_ffc.clear_ffcount;
|
|
tsp_ffc = &pps->ppsinfo_ffc.clear_timestamp;
|
|
pseq_ffc = &pps->ppsinfo_ffc.clear_sequence;
|
|
#endif
|
|
}
|
|
|
|
/*
|
|
* If the timecounter changed, we cannot compare the count values, so
|
|
* we have to drop the rest of the PPS-stuff until the next event.
|
|
*/
|
|
if (pps->ppstc != pps->capth->th_counter) {
|
|
pps->ppstc = pps->capth->th_counter;
|
|
*pcount = pps->capcount;
|
|
pps->ppscount[2] = pps->capcount;
|
|
return;
|
|
}
|
|
|
|
/* Convert the count to a timespec. */
|
|
tcount = pps->capcount - pps->capth->th_offset_count;
|
|
tcount &= pps->capth->th_counter->tc_counter_mask;
|
|
bt = pps->capth->th_bintime;
|
|
bintime_addx(&bt, pps->capth->th_scale * tcount);
|
|
bintime2timespec(&bt, &ts);
|
|
|
|
/* If the timecounter was wound up underneath us, bail out. */
|
|
atomic_thread_fence_acq();
|
|
if (pps->capgen != pps->capth->th_generation)
|
|
return;
|
|
|
|
*pcount = pps->capcount;
|
|
(*pseq)++;
|
|
*tsp = ts;
|
|
|
|
if (foff) {
|
|
timespecadd(tsp, osp, tsp);
|
|
if (tsp->tv_nsec < 0) {
|
|
tsp->tv_nsec += 1000000000;
|
|
tsp->tv_sec -= 1;
|
|
}
|
|
}
|
|
|
|
#ifdef FFCLOCK
|
|
*ffcount = pps->capffth->tick_ffcount + tcount;
|
|
bt = pps->capffth->tick_time;
|
|
ffclock_convert_delta(tcount, pps->capffth->cest.period, &bt);
|
|
bintime_add(&bt, &pps->capffth->tick_time);
|
|
bintime2timespec(&bt, &ts);
|
|
(*pseq_ffc)++;
|
|
*tsp_ffc = ts;
|
|
#endif
|
|
|
|
#ifdef PPS_SYNC
|
|
if (fhard) {
|
|
uint64_t scale;
|
|
|
|
/*
|
|
* Feed the NTP PLL/FLL.
|
|
* The FLL wants to know how many (hardware) nanoseconds
|
|
* elapsed since the previous event.
|
|
*/
|
|
tcount = pps->capcount - pps->ppscount[2];
|
|
pps->ppscount[2] = pps->capcount;
|
|
tcount &= pps->capth->th_counter->tc_counter_mask;
|
|
scale = (uint64_t)1 << 63;
|
|
scale /= pps->capth->th_counter->tc_frequency;
|
|
scale *= 2;
|
|
bt.sec = 0;
|
|
bt.frac = 0;
|
|
bintime_addx(&bt, scale * tcount);
|
|
bintime2timespec(&bt, &ts);
|
|
hardpps(tsp, ts.tv_nsec + 1000000000 * ts.tv_sec);
|
|
}
|
|
#endif
|
|
|
|
/* Wakeup anyone sleeping in pps_fetch(). */
|
|
wakeup(pps);
|
|
}
|
|
|
|
/*
|
|
* Timecounters need to be updated every so often to prevent the hardware
|
|
* counter from overflowing. Updating also recalculates the cached values
|
|
* used by the get*() family of functions, so their precision depends on
|
|
* the update frequency.
|
|
*/
|
|
|
|
static int tc_tick;
|
|
SYSCTL_INT(_kern_timecounter, OID_AUTO, tick, CTLFLAG_RD, &tc_tick, 0,
|
|
"Approximate number of hardclock ticks in a millisecond");
|
|
|
|
void
|
|
tc_ticktock(int cnt)
|
|
{
|
|
static int count;
|
|
|
|
if (mtx_trylock_spin(&tc_setclock_mtx)) {
|
|
count += cnt;
|
|
if (count >= tc_tick) {
|
|
count = 0;
|
|
tc_windup(NULL);
|
|
}
|
|
mtx_unlock_spin(&tc_setclock_mtx);
|
|
}
|
|
}
|
|
|
|
static void __inline
|
|
tc_adjprecision(void)
|
|
{
|
|
int t;
|
|
|
|
if (tc_timepercentage > 0) {
|
|
t = (99 + tc_timepercentage) / tc_timepercentage;
|
|
tc_precexp = fls(t + (t >> 1)) - 1;
|
|
FREQ2BT(hz / tc_tick, &bt_timethreshold);
|
|
FREQ2BT(hz, &bt_tickthreshold);
|
|
bintime_shift(&bt_timethreshold, tc_precexp);
|
|
bintime_shift(&bt_tickthreshold, tc_precexp);
|
|
} else {
|
|
tc_precexp = 31;
|
|
bt_timethreshold.sec = INT_MAX;
|
|
bt_timethreshold.frac = ~(uint64_t)0;
|
|
bt_tickthreshold = bt_timethreshold;
|
|
}
|
|
sbt_timethreshold = bttosbt(bt_timethreshold);
|
|
sbt_tickthreshold = bttosbt(bt_tickthreshold);
|
|
}
|
|
|
|
static int
|
|
sysctl_kern_timecounter_adjprecision(SYSCTL_HANDLER_ARGS)
|
|
{
|
|
int error, val;
|
|
|
|
val = tc_timepercentage;
|
|
error = sysctl_handle_int(oidp, &val, 0, req);
|
|
if (error != 0 || req->newptr == NULL)
|
|
return (error);
|
|
tc_timepercentage = val;
|
|
if (cold)
|
|
goto done;
|
|
tc_adjprecision();
|
|
done:
|
|
return (0);
|
|
}
|
|
|
|
/* Set up the requested number of timehands. */
|
|
static void
|
|
inittimehands(void *dummy)
|
|
{
|
|
struct timehands *thp;
|
|
int i;
|
|
|
|
TUNABLE_INT_FETCH("kern.timecounter.timehands_count",
|
|
&timehands_count);
|
|
if (timehands_count < 1)
|
|
timehands_count = 1;
|
|
if (timehands_count > nitems(ths))
|
|
timehands_count = nitems(ths);
|
|
for (i = 1, thp = &ths[0]; i < timehands_count; thp = &ths[i++])
|
|
thp->th_next = &ths[i];
|
|
thp->th_next = &ths[0];
|
|
|
|
TUNABLE_STR_FETCH("kern.timecounter.hardware", tc_from_tunable,
|
|
sizeof(tc_from_tunable));
|
|
|
|
mtx_init(&tc_lock, "tc", NULL, MTX_DEF);
|
|
}
|
|
SYSINIT(timehands, SI_SUB_TUNABLES, SI_ORDER_ANY, inittimehands, NULL);
|
|
|
|
static void
|
|
inittimecounter(void *dummy)
|
|
{
|
|
u_int p;
|
|
int tick_rate;
|
|
|
|
/*
|
|
* Set the initial timeout to
|
|
* max(1, <approx. number of hardclock ticks in a millisecond>).
|
|
* People should probably not use the sysctl to set the timeout
|
|
* to smaller than its initial value, since that value is the
|
|
* smallest reasonable one. If they want better timestamps they
|
|
* should use the non-"get"* functions.
|
|
*/
|
|
if (hz > 1000)
|
|
tc_tick = (hz + 500) / 1000;
|
|
else
|
|
tc_tick = 1;
|
|
tc_adjprecision();
|
|
FREQ2BT(hz, &tick_bt);
|
|
tick_sbt = bttosbt(tick_bt);
|
|
tick_rate = hz / tc_tick;
|
|
FREQ2BT(tick_rate, &tc_tick_bt);
|
|
tc_tick_sbt = bttosbt(tc_tick_bt);
|
|
p = (tc_tick * 1000000) / hz;
|
|
printf("Timecounters tick every %d.%03u msec\n", p / 1000, p % 1000);
|
|
|
|
#ifdef FFCLOCK
|
|
ffclock_init();
|
|
#endif
|
|
|
|
/* warm up new timecounter (again) and get rolling. */
|
|
(void)timecounter->tc_get_timecount(timecounter);
|
|
mtx_lock_spin(&tc_setclock_mtx);
|
|
tc_windup(NULL);
|
|
mtx_unlock_spin(&tc_setclock_mtx);
|
|
}
|
|
|
|
SYSINIT(timecounter, SI_SUB_CLOCKS, SI_ORDER_SECOND, inittimecounter, NULL);
|
|
|
|
/* Cpu tick handling -------------------------------------------------*/
|
|
|
|
static bool cpu_tick_variable;
|
|
static uint64_t cpu_tick_frequency;
|
|
|
|
DPCPU_DEFINE_STATIC(uint64_t, tc_cpu_ticks_base);
|
|
DPCPU_DEFINE_STATIC(unsigned, tc_cpu_ticks_last);
|
|
|
|
static uint64_t
|
|
tc_cpu_ticks(void)
|
|
{
|
|
struct timecounter *tc;
|
|
uint64_t res, *base;
|
|
unsigned u, *last;
|
|
|
|
critical_enter();
|
|
base = DPCPU_PTR(tc_cpu_ticks_base);
|
|
last = DPCPU_PTR(tc_cpu_ticks_last);
|
|
tc = timehands->th_counter;
|
|
u = tc->tc_get_timecount(tc) & tc->tc_counter_mask;
|
|
if (u < *last)
|
|
*base += (uint64_t)tc->tc_counter_mask + 1;
|
|
*last = u;
|
|
res = u + *base;
|
|
critical_exit();
|
|
return (res);
|
|
}
|
|
|
|
void
|
|
cpu_tick_calibration(void)
|
|
{
|
|
static time_t last_calib;
|
|
|
|
if (time_uptime != last_calib && !(time_uptime & 0xf)) {
|
|
cpu_tick_calibrate(0);
|
|
last_calib = time_uptime;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* This function gets called every 16 seconds on only one designated
|
|
* CPU in the system from hardclock() via cpu_tick_calibration()().
|
|
*
|
|
* Whenever the real time clock is stepped we get called with reset=1
|
|
* to make sure we handle suspend/resume and similar events correctly.
|
|
*/
|
|
|
|
static void
|
|
cpu_tick_calibrate(int reset)
|
|
{
|
|
static uint64_t c_last;
|
|
uint64_t c_this, c_delta;
|
|
static struct bintime t_last;
|
|
struct bintime t_this, t_delta;
|
|
uint32_t divi;
|
|
|
|
if (reset) {
|
|
/* The clock was stepped, abort & reset */
|
|
t_last.sec = 0;
|
|
return;
|
|
}
|
|
|
|
/* we don't calibrate fixed rate cputicks */
|
|
if (!cpu_tick_variable)
|
|
return;
|
|
|
|
getbinuptime(&t_this);
|
|
c_this = cpu_ticks();
|
|
if (t_last.sec != 0) {
|
|
c_delta = c_this - c_last;
|
|
t_delta = t_this;
|
|
bintime_sub(&t_delta, &t_last);
|
|
/*
|
|
* Headroom:
|
|
* 2^(64-20) / 16[s] =
|
|
* 2^(44) / 16[s] =
|
|
* 17.592.186.044.416 / 16 =
|
|
* 1.099.511.627.776 [Hz]
|
|
*/
|
|
divi = t_delta.sec << 20;
|
|
divi |= t_delta.frac >> (64 - 20);
|
|
c_delta <<= 20;
|
|
c_delta /= divi;
|
|
if (c_delta > cpu_tick_frequency) {
|
|
if (0 && bootverbose)
|
|
printf("cpu_tick increased to %ju Hz\n",
|
|
c_delta);
|
|
cpu_tick_frequency = c_delta;
|
|
}
|
|
}
|
|
c_last = c_this;
|
|
t_last = t_this;
|
|
}
|
|
|
|
void
|
|
set_cputicker(cpu_tick_f *func, uint64_t freq, bool isvariable)
|
|
{
|
|
|
|
if (func == NULL) {
|
|
cpu_ticks = tc_cpu_ticks;
|
|
} else {
|
|
cpu_tick_frequency = freq;
|
|
cpu_tick_variable = isvariable;
|
|
cpu_ticks = func;
|
|
}
|
|
}
|
|
|
|
uint64_t
|
|
cpu_tickrate(void)
|
|
{
|
|
|
|
if (cpu_ticks == tc_cpu_ticks)
|
|
return (tc_getfrequency());
|
|
return (cpu_tick_frequency);
|
|
}
|
|
|
|
/*
|
|
* We need to be slightly careful converting cputicks to microseconds.
|
|
* There is plenty of margin in 64 bits of microseconds (half a million
|
|
* years) and in 64 bits at 4 GHz (146 years), but if we do a multiply
|
|
* before divide conversion (to retain precision) we find that the
|
|
* margin shrinks to 1.5 hours (one millionth of 146y).
|
|
*/
|
|
|
|
uint64_t
|
|
cputick2usec(uint64_t tick)
|
|
{
|
|
uint64_t tr;
|
|
tr = cpu_tickrate();
|
|
return ((tick / tr) * 1000000ULL) + ((tick % tr) * 1000000ULL) / tr;
|
|
}
|
|
|
|
cpu_tick_f *cpu_ticks = tc_cpu_ticks;
|
|
|
|
static int vdso_th_enable = 1;
|
|
static int
|
|
sysctl_fast_gettime(SYSCTL_HANDLER_ARGS)
|
|
{
|
|
int old_vdso_th_enable, error;
|
|
|
|
old_vdso_th_enable = vdso_th_enable;
|
|
error = sysctl_handle_int(oidp, &old_vdso_th_enable, 0, req);
|
|
if (error != 0)
|
|
return (error);
|
|
vdso_th_enable = old_vdso_th_enable;
|
|
return (0);
|
|
}
|
|
SYSCTL_PROC(_kern_timecounter, OID_AUTO, fast_gettime,
|
|
CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_MPSAFE,
|
|
NULL, 0, sysctl_fast_gettime, "I", "Enable fast time of day");
|
|
|
|
uint32_t
|
|
tc_fill_vdso_timehands(struct vdso_timehands *vdso_th)
|
|
{
|
|
struct timehands *th;
|
|
uint32_t enabled;
|
|
|
|
th = timehands;
|
|
vdso_th->th_scale = th->th_scale;
|
|
vdso_th->th_offset_count = th->th_offset_count;
|
|
vdso_th->th_counter_mask = th->th_counter->tc_counter_mask;
|
|
vdso_th->th_offset = th->th_offset;
|
|
vdso_th->th_boottime = th->th_boottime;
|
|
if (th->th_counter->tc_fill_vdso_timehands != NULL) {
|
|
enabled = th->th_counter->tc_fill_vdso_timehands(vdso_th,
|
|
th->th_counter);
|
|
} else
|
|
enabled = 0;
|
|
if (!vdso_th_enable)
|
|
enabled = 0;
|
|
return (enabled);
|
|
}
|
|
|
|
#ifdef COMPAT_FREEBSD32
|
|
uint32_t
|
|
tc_fill_vdso_timehands32(struct vdso_timehands32 *vdso_th32)
|
|
{
|
|
struct timehands *th;
|
|
uint32_t enabled;
|
|
|
|
th = timehands;
|
|
*(uint64_t *)&vdso_th32->th_scale[0] = th->th_scale;
|
|
vdso_th32->th_offset_count = th->th_offset_count;
|
|
vdso_th32->th_counter_mask = th->th_counter->tc_counter_mask;
|
|
vdso_th32->th_offset.sec = th->th_offset.sec;
|
|
*(uint64_t *)&vdso_th32->th_offset.frac[0] = th->th_offset.frac;
|
|
vdso_th32->th_boottime.sec = th->th_boottime.sec;
|
|
*(uint64_t *)&vdso_th32->th_boottime.frac[0] = th->th_boottime.frac;
|
|
if (th->th_counter->tc_fill_vdso_timehands32 != NULL) {
|
|
enabled = th->th_counter->tc_fill_vdso_timehands32(vdso_th32,
|
|
th->th_counter);
|
|
} else
|
|
enabled = 0;
|
|
if (!vdso_th_enable)
|
|
enabled = 0;
|
|
return (enabled);
|
|
}
|
|
#endif
|
|
|
|
#include "opt_ddb.h"
|
|
#ifdef DDB
|
|
#include <ddb/ddb.h>
|
|
|
|
DB_SHOW_COMMAND(timecounter, db_show_timecounter)
|
|
{
|
|
struct timehands *th;
|
|
struct timecounter *tc;
|
|
u_int val1, val2;
|
|
|
|
th = timehands;
|
|
tc = th->th_counter;
|
|
val1 = tc->tc_get_timecount(tc);
|
|
__compiler_membar();
|
|
val2 = tc->tc_get_timecount(tc);
|
|
|
|
db_printf("timecounter %p %s\n", tc, tc->tc_name);
|
|
db_printf(" mask %#x freq %ju qual %d flags %#x priv %p\n",
|
|
tc->tc_counter_mask, (uintmax_t)tc->tc_frequency, tc->tc_quality,
|
|
tc->tc_flags, tc->tc_priv);
|
|
db_printf(" val %#x %#x\n", val1, val2);
|
|
db_printf("timehands adj %#jx scale %#jx ldelta %d off_cnt %d gen %d\n",
|
|
(uintmax_t)th->th_adjustment, (uintmax_t)th->th_scale,
|
|
th->th_large_delta, th->th_offset_count, th->th_generation);
|
|
db_printf(" offset %jd %jd boottime %jd %jd\n",
|
|
(intmax_t)th->th_offset.sec, (uintmax_t)th->th_offset.frac,
|
|
(intmax_t)th->th_boottime.sec, (uintmax_t)th->th_boottime.frac);
|
|
}
|
|
#endif
|